Early indications in the Palestinian presidential elections show former Prime Minister Mahmoud Abbas is set to win by a comfortable margin.

Polling closed at 1900 GMT, two hours later than scheduled after voting difficulties forced an extension.

One exit poll, by the Palestinian Centre for Policy and Survey Research, gave Mr Abbas 66% of the vote and his closest challenger, Mustafa Barghouti, 19.7%.

A high margin of victory, as well as good voter turnout, are considered crucial if Mr Abbas is to command enough of a mandate to push through his agenda of peace talks and an end to the armed Palestinian uprising.

Although a final result is not expected until tomorrow, supporters of Mr Abbas are already celebrating.

Voter problems

This is the first presidential election for Palestinians since 1996, and about 1.1 million people registered to vote.

There were problems with registration, heavy turnout and the turning away of hundreds of voters from a big Israeli-run polling station in East Jerusalem.

East Jerusalem has special voting arrangements, with Palestinians allowed to vote in Israeli post offices.

Voters complained Israeli officials were not allowing them to vote even though the Palestinian central election commission had properly registered them.

Mr Abbas himself cast his vote at the Ramallah compound where the late leader of the Palestinians Yasser Arafat is buried. He said the vote was taking place in a "marvellous" fashion.

"It is an illustration of how the Palestinian people aspire to democracy," he said.

Renewed hope

The death of Mr Arafat in November last year has raised hopes for new peace talks between the Palestinians and Israelis.

The Israeli Prime Minister, Ariel Sharon, had refused to do business with Mr Arafat.

Mr Abbas, also known as Abu Mazen, is the nominated candidate and a founding member of the main Palestinian political faction, Fatah.

He is widely regarded as a moderate and is considered to have been the main architect of the Oslo Peace Accord which came close to resolving the conflict in the early 1990s.

He served as prime minister to Yasser Arafat in 2003 but resigned again after four months of a power struggle in which Arafat refused to hand over crucial powers to him.

He became chairman of the Palestinian Liberation Organisation after Arafat's death and has been the front-runner to succeed him ever since.